In German CHDK forum a project for 12bit curves was launched in 2010! CHDKLover had revised the curve function completely. It was a great work.
See also the German description: http://forum.chdk-treff.de/viewtopic.php?f=7&t=1889&start=60#p26541
In 2012 I have adapted the patch to the CHDK version 1.2.
Since the curves feature is in a module, integrating this rework would probably be a good idea (1.4?).
Some random thoughts though (only looked in the patch, did not try it):
- RGB curves seem to assume RGGB CFA pattern
- some old options (+1EV, etc.) will disappear from the menu
- stuff like #if CAM_SENSOR_BITS_PER_PIXEL==12 will need to be replaced by runtime checks based on camera_info structures
But the interest was not very big.
Yes, this is probably one of the less frequently used features, but some people might like it. Since all new cameras (except g1x') have 12bit RAW, none of those can use curves currently.
